What it is
The ABB ACS580-01-027A-4 sits in the ACS580 family as a general-purpose variable frequency drive, three-phase, rated 480 V AC, in a wall-mount NEMA 1 enclosure on an R3 frame measuring 20.93" H × 8.16" W × 9.33" D. ABB publishes two operating points on this code: normal duty at 20 Hp with 27 A output current, and heavy duty at 15 Hp with 21 A output current. The duty split is the figure to match against the load, not the headline nameplate — a constant-torque conveyor or extruder wants the heavy-duty 15 Hp / 21 A envelope, while a fan or centrifugal pump can ride the normal-duty 20 Hp / 27 A point with margin to spare. Supply-side the drive accepts 480 V AC and produces a three-phase output, matching the stated supply range on the data sheet for direct connection to a 480 V US distribution.
Sizing the motor to the drive
On a 480 V three-phase feed, the 27 A normal-duty current figure maps roughly to a 20 Hp four-pole induction motor, and the 21 A heavy-duty figure maps to 15 Hp — those are the two ABB-rated match points and they are the only ones the warranty paperwork will treat as in-spec. If the driven load is constant torque (mixers, compressors, conveyors with high breakaway), spec to the 15 Hp / 21 A heavy-duty point. If the load is variable torque (HVAC fans, centrifugal pumps), the 20 Hp / 27 A normal-duty point carries the motor with thermal headroom and lets a slightly larger motor ride on the same drive.
Same-family cross-shop
The next-step sibling in the ACS580-01 line at 480 V is the ACS580-01-034A-4, listed at 25 Hp on the same three-phase 480 V AC platform. It sits one current step above this code and is a like-for-like swap when the motor on the nameplate is closer to 25 Hp than 20 Hp — same family, same wall-mount NEMA 1 form factor, different output current.
Panel integration
The R3 frame at 8.16" W and 9.33" D sets the wall area the panel builder needs to leave clear above and below the unit for heatsink airflow; cabinet cooling should be sized to the drive's own thermal curve rather than the panel's nameplate ambient.